This invention relates generally to scalping apparatus for sugar beets and like plants, relates particularly to disc scalping apparatus, and specifically relates to nonpowered disc scalping apparatus.
Prior to lifting, the leaves and stems are desired to be removed from sugar beets. This is conventionally performed by a defoliator which typically includes one or more rotors which are rotated to cut the greens or foliage of the beets. The defoliator further typically includes a scalper which cuts any remaining leaves as well as the stem from the beets while the beets are in the ground. Prior scalpers are generally of three types, i.e. a stationary blade, a powered disc, or a nonpowered disc with a stationary blade scalper, a blade is held at an angle to the row as the defoliator is moved parallel to the row. The major problem with blade scalpers is that the blades become dull due to the close proximity to the ground and beet leaves and other debris tend to wrap around the cutting edge of the blade. Powered disc scalpers such as the type shown in U.S. Pat. No. 3,583,136, but which currently are powered by hydraulic motors, have less tendency to be wrapped by debris but are relatively expensive to manufacture and maintain. Prior nonpowered disc scalpers, while avoiding the costs of the drive components of prior powered disc scalpers, had difficulty in keeping the disc rotating and did not operate very well. Thus, prior to the present invention, nonpowered disc scalpers did not have large market acceptance.
Thus, a need exists for improved scalpers which avoid the disadvantages and shortcomings of prior scalpers.